A semiconductor device is generally formed in a multi-layer structure. Each layer of such a multi-layer structure is typically formed by means of a sputtering method, a chemical vapor deposition method, or other growth or deposition method, and may be patterned by subjecting the layer to a lithography process.
However, several problems may occur in a semiconductor device due to the differences of pattern size and pattern density, for example, on a substrate of the semiconductor device. Accordingly, technologies are being developed to form dummy patterns along with a main pattern for the device.
FIGS. 1A to 1C are concept views of a layout method for a mask according to a related art.
According to the related art, a cell 10 to be inserted into a main chip 50 layout is first formed as in FIG. 1A. That is, a main pattern 2 in a cell and a dummy pattern 4 in a cell are formed on the basis of the cell 10.
Thereafter, the cell 10 in which the main pattern 2 in the cell and the dummy pattern 4 in the cell are formed is inserted into the main chip 50 layout as in FIG. 1B. The main chip 50 is provided with main patterns 30, 40 of the chip.
Meanwhile, a cell 20 rotated within the main chip 50 can be inserted in some cases as shown in FIG. 1B.
However, when the rotated cell 20 is inserted, the case where the spacing S between the main pattern 40 of the main chip and a dummy pattern 4a in the rotated cell 20 is less than a minimum design rule spacing between the patterns can occur.
At this time, referring to FIG. 1C, the dummy pattern 4a in the rotated cell 20 existing in the spacing less than the minimum design rule spacing is removed so as to avoid a design rule error. Therefore, the dummy pattern is formed in a different form from the first design of the dummy pattern in the cell 10.
Also, according to the related art, the dummy pattern is removed in the rotated cell 20, etc., contrary to expectation so that the patterns are formed in different form from the first design of the dummy pattern, thereby causing a problem where the uniformity between the patterns can not be obtained.